Yet, over time, Hutchings and others said, marine reserves can benefit local fishing communities as well the commercial fishing industry by increasing fish yields.
According to Charles Birkeland, a researcher at the University of Hawaii, the Philippines began establishing marine reserves in the mid-1970s and now has as many as 500. Support for the conservation measure grew, he said, after local people experienced the benefits. Several decades ago, a scientist helped villagers on Apo Island and Sumilon Island set up marine reserves, which demarcated 25 percent of the local reefs as "no-take" zones. Eventually, fish yields in the remaining 75 percent of the reefs nearly doubled.
The fish in the protected areas grew larger, were more plentiful, and produced more offspring, which also improved stocks in adjacent areas as the fish migrated and spawned, Birkeland said.
In a study designed to evaluate such spillover effects, reported late last year in Science, Roberts and his colleagues showed that the creation of marine sanctuaries off St. Lucia and Florida led to higher yields and larger fish in neighboring fisheries. "Reserves are like money in the bank," Roberts said at the meetings in Boston, "because what they do is protect the spawning stocks of fish."
But creating marine reserves isn't enough to revive fish populations that are declining rapidly to alarming levels, the scientists said. Among their recommendations, they called for a substantial reduction in the size of fishing fleets and the elimination of taxpayer subsidies that enable fishing boats to augment their technological capabilities.
Scramble to Exploit
According to the scientists, commercial fishing companies began tapping deep-water fisheries in the 1960s and 1970s, when shallow-water fisheries were yielding smaller catches. Fishing boats became more powerful, with sturdier winches, cables, and nets.
As fishing fleets traveled farther afield, previously unfamiliar species of deep-sea fish began showing up widely in international markets and on restaurant menus. The annual catches of some of these now-popular varieties, such as the species marketed as Chilean sea bass and orange roughy, have already declined significantly, according to data cited in Boston and in other scientific reports.
For example, stocks of orange roughy (Hoplostethus atlanticus)in some regions are less than 20 percent of what they were only a decade ago.
The fish dwells deep in the ocean and travels long distances to spawn above seamounts in the Southern Hemisphere. Protected in the deep, it can grow to 150 years old. Because of this long lifespan, it matures and reproduces relatively late in life.
In the 1980s, fishing fleets discovered the fish's spawning grounds off New Zealand and southern Australia. Catches were often remarkableas many as 60 tons in only 20 minutes of trawling. In the face of such intensive harvesting, H. atlanticus can't breed fast enough to ensure that the species will be available for future generations.
"If we want to keep seafood on our plates, we need refuges so some fish survive long enough to reproduce," said Roberts.
Going for Broke
Even as fish stocks steadily dwindle, there are no signs that commercial fishing companies will voluntarily change their practices because the soaring demand for fish continues to push up prices. Fish pricesespecially for prime species such as cod, haddock, and flounderhave risen as much as eight times the consumer price index over the past 20 years, according to Rosenberg.
"Fish is rapidly becoming a luxury in so many places that the prices are rising as dramatically as the harvest is falling," he said. "This means the big fishing operations have big incentives to extract even small fish, and it enables them to invest in even more technology and more powerful boats."
In Asia, reef fish are paying the price, according to Yvonne Sadovy, a scientist at the University of Hong Kong.
In the past, most of the locally consumed fish came from South China Sea waters, she noted, But, "as economies boomed and local fisheries became overfished, fishing boats began traveling farther away from Hong Kongas far east as Fiji and into the Indian Oceanlooking for supplies to keep up with the growing demand," she said.
Imports of live reef fish to Hong Kong increased from about 4,000 metric tons in 1988 to 30,000 metric tons in 2000, she said, adding that demand is particularly strong in China.
Live-fish carrier vessels, called viviers, can carry up to 30 metric tons of fish from reefs throughout much of the Indo-Pacific Ocean, Sadovy explained. The giant vessels often deploy smaller boats, as many as 20 per trip, to reach inner reef sites, and the fish are brought back to the mother ship for transport to major demand centers in Southeast Asia.
"The high prices paid for luxury live reef fish make such expensive operations possible," she said.
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